Hey J,
Before you get into lubing your cast bullets, you might want to know whether or not they were ever sized. Also, if they were sized, to what diameter? Are both types sized to the same diameter? What diameter do you want for your gun? If it is a fairly new .357, chances are .358 or .359 would work well for you. You can slug your barrel and check the diameter it is. One, two, or possibly even three thousandths over your diameter could work just fine.
I think you need to find out your barrel diameter and the size of the bullets you received. If your bullets are the right size, then you can get busy lubing them for shooting.
Another thing for consideration, the bullets could be sized for 9MM use, and they would not work for crap in a .357. Is there a local gun club where you might find some folks who are familiar with cast bullets and how to use them? You might also check the Cast Bullets forum to see if anyone in the Tucson area might be willing to help you.
Actually, I wouldn't mind being in Tuscon right now to give you a hand. I hate winters and would rather be in the warm stuff, but we had to give up our SnowBirding in 2010 due to medical problems. Good luck with your bullets.
Best wishes,
Dave Wile